1. Field of the Disclosed Subject Matter
The disclosed subject matter relates to roofing material, and in particular to a roofing material, a finished flake for a roofing material, and a method of making a finished flake. The finished flake can be used for roofs and also for sidewalls and other exterior surfaces exposed to the weather. Particularly, the disclosed subject matter relates to metal flake surfaced roofing materials, such as disclosed in U.S. Publication No. 2003/0091795, entitled “Metal Flake-Surfaced Roofing Materials” filed on Oct. 21, 2002; U.S. Pat. No. 8,197,893, entitled “Colored Metal Flake Surfaced Roofing Materials”; and U.S. Publication No. 2012/0270015, entitled “Colored Metal Flake Surfaced Roofing Materials” filed on May 11, 2012, the contents of each of which are hereby incorporated by reference in their entireties.
The roofing materials which may be surfaced with finished flakes include, but are not limited to, asphaltic roofing materials and non-asphaltic roofing materials such as concrete, plastic, rubber or metal roofing materials that have other materials on the exposed surface to provide a weathering surface or which are used for aesthetic purposes. Some known roofing materials use granules made of rock which can allow ultraviolet light to penetrate and denigrate the roofing material.
The disclosed subject matter further relates to a finished flake and a method of making a finished flake for a roofing material such that the finished flake includes structural and functional benefits, along with pleasing aesthetics as noted herein. Flakes may be coated with one or more coating materials, and may be applied to the surface of roofing materials as the sole surfacing material or in combination with other materials, such as conventional colored roofing granules. Any roofing material that uses colored roofing granules, crushed natural stone, or coatings on the exposed roofing surface can have finished flakes applied thereto, in place of or in addition to the roofing granules, crushed natural stone, or coatings, in accordance with the disclosed subject matter.
2. Description of the Related Art
Roofing materials, such as roofing shingles, are made from a wide variety of materials, including metal, slate, concrete, plastic, asphalt, etc.
Metal roofs can be aesthetically pleasing, durable, long lasting, lightweight, ecologically sound, fire retardant, and energy efficient. Metal roofs can be expensive, can require installation by a professional trained in metal roofing installation, and can be damaged or dented by outdoor elements, such as hail.
Slate roofs can have long life, fire resistance, high strength, relatively low maintenance, and an aesthetically distinctive appearance. Slate roofs, however, can be heavy and expensive. Further, slate exists in limited color choices, can be easily damaged (particularly during maintenance due to walking on the roof), and relies on underlayment which usually fails before the slate.
Asphalt roofing materials can have good performance in extreme temperatures and areas where wind, water and ice are of concern. In addition, asphalt roofing materials can offer enhanced efficiency in that they can be produced in high volume and can be easily installed, resulting in lower costs and improved overall value. Furthermore, asphalt roofs can be made with colored granules to produce a colored roofing surface tailored to desired color, reflectance, and emittance. However, many asphalt roofing materials do not have the same aesthetic qualities as metal and slate roofs and can have diminished life span in comparison. Additionally, such roofing materials can be expensive.
Pigment-coated mineral rocks are commonly used as color granules in roofing applications to increase the aesthetic and protective functions of asphalt shingles. Roofing granules typically are made of crushed and screened mineral materials that, subsequent to crushing and screening, can be coated with a binder containing one or more coloring pigments such as suitable metal oxides. The binder can be a soluble alkaline silicate that is subsequently insolubilized by heat or by chemical reaction, resulting in an insoluble colored coating on the mineral particles. Preparation of colored, coated roofing granules has long been known in the art such as disclosed in U.S. Pat. No. 2,981,636 of Lodge et al., the contents of which is incorporated herein by reference in its entirety. The granules are then employed to provide a protective layer on asphaltic roofing materials, such as shingles.
Pigments for roofing granules have usually been selected to provide shingles having an attractive appearance, with little concern for the thermal stresses encountered on shingled roofs. However, depending on location and climate, shingled roofs can experience very challenging environmental conditions, which tend to reduce the effective service life of such roofs. One such environmental stress is the elevated temperature experienced by roofing shingles under sunny, summer conditions, especially roofing shingles coated with dark colored roofing granules.
Asphalt shingles coated with conventional roofing granules are known to have low solar heat reflectance, and hence will absorb solar heat especially through the near infrared range (700 nm-2500 nm) of the solar spectrum. This heat absorption characteristic is increased as the granules covering the surface become darker in color. For example, white colored asphalt shingles can have solar reflectance (sometimes referred to as “tsr” or total solar reflectivity) in the range of approximately 25 to approximately 35 percent, whereas dark colored asphalt shingles may have solar reflectance of only approximately 5 to approximately 15 percent.
Accordingly, there exists a need for a roofing material with improved durability and aesthetic qualities. Thus, there is a continuing need for roofing materials that exhibit excellent reflectance, as well as emittance, characteristics while being aesthetically pleasing. The presently disclosed subject matter satisfies these and other needs.